What factor affects the luminosity of stars?

Answer 1

Energy output, as absolute brightness (magnitude) is taken at a standard distance of 10 parsecs.

Answer 2

There are 2 main factors: the size of the star and its surface temperature.

A larger size means a larger surface area to emit light.

A higher surface temperature increases the energy emitted.

Seen from Earth, the brightness of a star depends on how far away the star is as well as its actual luminosity.

Answer 3

There are two factors in the "visual magnitude" of a star, the number that we use to express its relative brightness in the sky. The first is the actual brightness or "absolute magnitude", and the second is distance.

After all, a car's headlight is WAY brighter than a candle flame - but a candle flame a foot away looks brighter than a headlight a mile away.

The brightest star in the sky is the Sun; it is only 93 million miles away, 8.2 light minutes from Earth. It has a "visual magnitude" of -26.7. The Sun is so bright that its glare can blind us, and we get sunburns in just a few minutes. It has an absolute magnitude of 4.6. (The lower the number, the brighter the star. A star with a magnitude of 1 is 10 times brighter than a star with a magnitude of 2.)

The second brightest star in the sky is Sirius, at 8.7 light YEARS away, with a visual magnitude of -1.5. Sirius is a bright dot in the black sky. It has an absolute magnitude of 1.4, which means that Sirius is actually over 1,000 times brighter than the Sun. But the Sun is close, and Sirius far away.

The CLOSEST star (other than the Sun) is Proxima Centauri, at a distance of 4.2 light years; HALF the distance to Sirius. Proxima Centauri is INVISIBLY DIM; you cannot see it without a telescope. Proxima Centauri is a red dwarf star, with a visual magnitude of 11.5 (7 is the dimmest star you can see with the naked eye) and an absolute magnitude of 15.5.

Answer 4

The luminosity of a star is primarily determined by its size and temperature. Larger stars tend to be more luminous because they have more surface area to emit light. Higher temperature stars emit more energy at shorter wavelengths, making them appear brighter.

Answer 5

• It's luminosity (Brightness)
• It's distance from the observer.
• The amount of "cover" - stellar debris in the way.

Answer 6

that it when it gets closer, it gets brighter